Well tbf its a standard in games that have some kind of law implemented ie. cops or guards. We could spin it the other way and for example use Skyrim, if you steal something there or harm any other NPC etc. guards will be on your ass, you can try to weasel it out by paying bounty but eitherway the law system works. The point im trying to make is that GTA is not the only example, Skyrim, FO, Watchdogs, Saints Row, Mafia etc. all of them games which have factions or hiearchy have at this point in time implemented such systems so it is acceptable that people/players expect this to be a norm/standard.
I think I can add a note here.
The design of NCPD NPC behavior is not bad, indeed, I can say they are really well designed. Taking the pursuit as an example, some mods had realized car chase, not only NCPD, members of different gangs can also follow V, get into their car to chase or get out of their car to shoot. Different police cars are called according to the wanted level.
This is not to show that Modder do more work than developers, on the contrary, the CDPR developers did very good and much more work, they left an almost finished system in game as those mod‘s foundation, they wrote all those behavior and well-tested, so Modders only need very simple code to call the existing functions in game.
But where is the problem? In those mods, I found that the problem lies in the AI navigation. There is a good NPC car summoning system and well-designed behavior scripts, but they can't chase as smoothly as designed, they will hit themselves to the buildings in the city. I think this is the reason why this feature is not implemented in the default version.
This is also the reason why I think NCPD behavior is relatively easy to fix - there is no need to build a totally new GTA-like system and consider unknown interactions. This is a system that has almost completed before release and only a small part of it not works well. If AI navigation and driving works, the police problem solves.
And—you know, if AI driving works, there would no be any big problem in taxi system and racing system, right? we can find taxi-related text in game, we can enter vehicle and trigger events, the problem is AI navigation, too.